Power tool

ABSTRACT

A power tool includes a motor disposed in a motor housing, a handle extending downward from the motor housing, a main switch provided on the handle and configured to switch the motor ON and OFF, and a state-changing operation part located on a lower portion of the motor housing or on an upper-end portion of the handle. The state-changing operation part is located upward of the main switch and is configured to effect a change of a rotational state of the motor, other than a direction of rotation of the motor, or an illumination level of a light.

CROSS-REFERENCE

The present application is a continuation application of U.S.application Ser. No. 15/880,728 filed on Jan. 26, 2018, now pending,which claims priority to Japanese patent application serial number2017-022415 filed on Feb. 9, 2017, the contents of which areincorporated fully herein by reference.

TECHNICAL FIELD

The present invention relates to a power tool such as an impact driver.

BACKGROUND ART

Japanese Patent No. 5627738 discloses an impact driver having a switchpanel, which is capable of performing a switching operation to change anoperating mode of the power tool and is provided on a lower-end side ofa handle part (grip).

SUMMARY

However, because the switch panel of Japanese Patent No. 5627738 isprovided on the lower-end side of the handle part, to operate the switchpanel reliably, the user must operate the switch panel with one handwhile supporting the impact driver with the other hand; therefore, themodes of operation and ease of operation are limited.

A principal object of the present teachings is to provide a power toolhaving an improved ease of operation, i.e. to provide a more ergonomicalpower tool.

In a first aspect of the present teachings, a power tool comprises: amotor; a main-body part (motor housing), in which the motor is disposed;a handle part, which extends downward from the main-body part; a mainswitch, which is provided on the handle part and switches the motor ONand OFF; and a state-changing operation part (state-changingmanipulation part), which is located on a lower part of the main-bodypart or an upper-end part of the handle part, is provided upward of themain switch, and changes a rotational state, other than the rotationaldirection, of the motor.

In a second aspect of the present teachings, a power tool comprises: amotor; a main-body part (motor housing), in which the motor is disposed;a handle part, which extends downward from the main-body part; a mainswitch, which is provided on the handle part and switches the motor ONand OFF; a light, which radiates light; and a state-changing operationpart (state-changing manipulation part), which is located on a lowerpart of the main-body part or an upper-end part of the handle part, isprovided upward of the main switch, and changes the lamp ON/OFF state ofthe light.

In a third aspect of the present teachings, the state-changing operationpart is disposed forward of the main switch.

In a fourth aspect of the present teachings, a power tool comprises: amotor; a main-body part (motor housing), in which the motor is disposed;a handle part, which extends downward from the main-body part; a mainswitch, which is provided on the handle part and switches the motor ONand OFF; and a state-switching switch, which is located on a front-endpart or a rear-end part of the main-body part or is located on afront-end part or a rear-end part of an upper-end part of the handlepart, is provided upward of the main switch, and switches a rotationalstate of the motor.

In a fifth aspect of the present teachings, a power tool comprises: amotor; a main-body part (motor housing), in which the motor is disposed;a handle part, which extends downward from the main-body part; a mainswitch, which is provided on the handle part and switches the motor ONand OFF; a light, which radiates light; and a state-switching switch,which is located on a front-end part or a rear-end part of the main-bodypart or is located on a front-end part or a rear-end part of anupper-end part of the handle part, is provided upward of the mainswitch, and switches the lamp ON/OFF state of the light.

In a sixth aspect of the present teachings, the state-switching switchis provided on a (the) lower part of the main-body part.

A principal effect of the present teachings is that a power tool havingan improved ease of operation is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view, viewed from the front, of an impact driveraccording to a first embodiment of the present teachings.

FIG. 2 is a front view of the impact driver shown in FIG. 1.

FIG. 3 is a right view of the impact driver shown in FIG. 1.

FIG. 4 is a center longitudinal-cross-sectional view of the impactdriver shown in FIG. 1.

FIG. 5 is an enlarged view of an upper part of the impact driver shownin FIG. 4.

FIG. 6 is a transverse cross-sectional view of a portion between amain-body part and a trigger shown in FIG. 1.

FIG. 7 is a cross-sectional view taken along line A-A in FIG. 3.

FIG. 8 is a block diagram of the principal parts of a controlling meansaccording to the impact driver shown in FIG. 1.

FIG. 9 is a flow chart related to the control of a state-changingoperation part performed by the controlling means shown in FIG. 8.

FIG. 10 is a drawing, corresponding to FIG. 1, of an impact driveraccording to a second embodiment of the present teachings.

FIG. 11 is a drawing, corresponding to FIG. 2, of the impact driveraccording to the second embodiment.

FIG. 12 is a drawing, corresponding to FIG. 3, of the impact driveraccording to the second embodiment.

FIG. 13 is a drawing, corresponding to FIG. 5, of the impact driveraccording to the second embodiment.

FIG. 14 is a center transverse-cross-sectional view of the main-bodypart in FIG. 10.

FIG. 15 is a cross-sectional view taken along line B-B in FIG. 12.

FIGS. 16A and 16B are flow charts, corresponding to FIG. 9, related tothe control of a state-changing operation part performed by thecontrolling means shown in FIG. 8.

FIG. 17 is an oblique view, viewed from the rear, of an impact driveraccording to a third embodiment of the present teachings.

FIG. 18 is a rear view of the impact driver shown in FIG. 17.

FIG. 19 is a drawing, corresponding to FIG. 5, of the impact driveraccording to the third embodiment.

FIG. 20 is a drawing, corresponding to FIG. 5, of the impact driveraccording to the third embodiment.

FIG. 21 is a drawing, corresponding to FIG. 14, of the impact driveraccording to the third embodiment.

FIG. 22 is a cross-sectional view taken along line C-C in FIG. 19.

FIG. 23 is a drawing, corresponding to FIG. 1, of an impact driveraccording to a fourth embodiment.

FIG. 24 is a drawing, corresponding to FIG. 2, of the impact driveraccording to the fourth embodiment.

FIG. 25 is a drawing, corresponding to FIG. 3, of the impact driveraccording to the fourth embodiment.

FIG. 26 is a drawing, corresponding to FIG. 5, of the impact driveraccording to the fourth embodiment.

FIG. 27 is a drawing, corresponding to FIG. 6, of the impact driveraccording to the fourth embodiment.

FIG. 28 is a cross-sectional view taken along line D-D in FIG. 25.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Representative embodiments and modified examples thereof of the presentteachings are explained below, referencing the drawings whereappropriate.

Front, rear, up, down, left, and right in these embodiments and modifiedexamples are defined for the sake of convenience of explanation and maychange based on, for example, the work situation, the state of a memberthat moves, or the like.

It is noted that the present invention is not limited to the embodimentsand modified examples described below.

First Embodiment

FIG. 1 is an oblique view, viewed from the front, of an impact driver 1according to a first embodiment of the present teachings, which is oneexample of a rotary-impact tool that is one representative, non-limitingexample of a power tool according to the present teachings; FIG. 2 is afront view of the impact driver 1; FIG. 3 is a right view of the impactdriver 1; FIG. 4 is a center longitudinal-cross-sectional view of theimpact driver 1 (note that a battery is not shown in cross section);FIG. 5 is an enlarged view of an upper part of FIG. 4; FIG. 6 is atransverse cross-sectional view of a portion between a main-body partand a trigger of the impact driver 1; and FIG. 7 is a cross-sectionalview taken along line A-A in FIG. 3.

The impact driver 1 comprises a housing 2, which forms the outer wall ofthe impact driver 1.

The impact driver 1 comprises a circular-column shaped main-body part 4,whose central axis is set to the front-rear direction, and a handle part6, which is formed such that it protrudes downward from a lower part ofthe main-body part 4. It is noted that, in FIGS. 3, 4, the right is thefront.

The handle part 6 is a portion that is grasped by the user, and a mainswitch 7 is disposed on an upper-end part of the handle part 6. The mainswitch 7 comprises a trigger 8, which is capable of an operation(manipulation) in which the user pulls the main switch 7 with his or herfingertip, and a main-switch main-body part 9, which switches the mainswitch 7 ON and OFF based on the operation of the trigger 8. The trigger8 protrudes from the main-switch main-body part 9 and is visible on thehousing 2 (an upper-front part of the handle part 6). The main-switchmain-body part 9 is disposed inside the housing 2.

In order from the rear side, a fan 10, a motor 11, a planetary-gearmechanism 12 that is a speed-reducing mechanism, a spindle 13, a coilspring 14 that is an elastic member, a hammer 16, and an anvil 17 arecoaxially inserted (disposed) in the main-body part 4 of the impactdriver 1. It is noted that the arrangement of the various members inand/or one the various housings, cases, and the like shall include, asappropriate, an arrangement (embodiment) in which the members(components) are completely contained in the housings, the cases, andthe like, and an arrangement (embodiment) in which some of the membersare contained in the housings, the cases, and the like, and theremaining members protrude or are visible from the housings, the cases,and the like.

The motor 11 is the drive source of the impact driver 1; the rotation ofthe motor 11 is transmitted to the spindle 13. Furthermore, therotational force of the spindle 13 is converted, if appropriate, into arotational impact force (at least one of a rotational force and animpact force) by the hammer 16, etc. (an impact-mechanism part), and,while being cushioned as appropriate by the spring 14 that extendsbetween the spindle 13 and the hammer 16, is transmitted to the anvil17, which serves as an output shaft. The anvil 17 is a member thatreceives the rotational impact force and is capable of rotating about anaxis; the anvil 17 receives a bit (tool accessory), which is not shown.A driver can be used as the bit, and the impact driver 1 can be used fortightening screws.

The housing 2 comprises a left motor housing 18 and a right motorhousing 19, which are each half-housing shaped and together define amotor housing, a rear cover 20, and a tube-shaped hammer case 21. Theleft motor housing 18 comprises a plurality of screw-boss parts 22, 22,. . . , and the right motor housing 19 has screw holes corresponding tothe screw-boss parts 22, 22, . . . . The left motor housing 18 and theright motor housing 19 are joined together by screws 23, 23, . . . ,which enter the screw holes and the screw-boss parts 22, 22, . . . .

The left motor housing 18 and the right motor housing 19 extend from arear part (excluding a rear-end part) of the main-body part 4 to thehandle part 6. A portion of the left motor housing 18 and the rightmotor housing 19 that is adjacent the rear-end part of the main-bodypart 4 is an opening.

Air-exhaust ports 24, 24, . . . , which are arranged in the up-downdirection, are provided on both sides of a rear part of the rear cover20 (an outer-wall portion of the main-body part 4); and air-suctionports 25, 25, . . . , which are arranged in the front-rear direction,are provided forward of the air-exhaust ports 24, 24, . . . above andbelow (an outer-wall portion of the main-body part 4) on both sides ofthe rear parts of the left motor housing 18 and the right motor housing19.

The rear cover 20 widens in the up-down direction and the left-rightdirection and is secured by screws (not shown) in the state in which therear cover 20 covers the opening in the left motor housing 18 and theright motor housing 19 (i.e., is disposed on the rear-end part of themain-body part 4).

The hammer case 21 is a bell-shaped member, wherein the diameter of afront part is smaller than that of a rear part, and forms an outer wallof a front part of the main-body part 4. A rear part of the hammer case21 is contained in the opening formed in front-end parts of the leftmotor housing 18 and the right motor housing 19 of the main-body part 4.

A tube-shaped cover 26 is disposed on an outer side of a center part ofthe hammer case 21 in the front-rear direction, and a ring-shaped bumper27, which is formed of an elastic body, is disposed on an outer side ofthe front-end part of the hammer case 21.

Between the main-body part 4 and the handle part 6 and rearward of thetrigger 8, a forward/reverse switching lever 28, which is a switch thatswitches the rotational direction of the motor 11, is provided such thatit passes through the housing 2 in the left-right direction.

A lower-end part of the handle part 6 constitutes a battery-mountingpart 29, which widens outward with respect to the upper part of thehandle part 6, and a battery 31, which is capable of being mounted anddismounted (removed) by using (pushing) a battery button (lever) 30, isheld (supported) downward of the battery-mounting part 29. The battery31 is, e.g., a 14.4 V (volt) lithium-ion battery, and eight cells, whichare not shown, are contained inside a battery case, which is made ofresin. Each cell has a circular-column (cylindrical) shape that iselongated in an axial direction and is oriented in a left-rightdirection.

A controller 33, which comprises a circuit board, is contained in aninner part of the battery-mounting part 29. A switching device forvarying the speed of the motor 11 is installed in the controller 33.

The battery 31 comprises a battery-terminal part on its upper surfaceand comprises a raised part 34 on its front-upper part. The battery 31is mounted by being slid rearward from the front of the battery-mountingpart 29. When being mounted, a rear part of the raised part 34 makescontact with a front part of the battery-mounting part 29, and thebattery-terminal part contacts a terminal 35, which is incorporated inthe battery-mounting part 29. The terminal 35 is electrically connectedto the controller 33. In addition, during mounting, a battery tab 36,which is biased upward by the elastic member (not shown) and protrudesfrom the upper surface of another portion of the battery 31, enters abattery-mounting recessed part 37, which is hollowed upward and providedon a lower-front part of the battery-mounting part 29. On the otherhand, when the battery 31 is dismounted (removed), the battery button(lever) 30, which is connected to the elastic member of the battery tab36, is operated (pressed), and the battery 31 is slid forward whilemaintaining the state in which the battery tab 36 is separated from thebattery-mounting recessed part 37.

Hook grooves 39, to which a hook 38 can attach, are provided on the leftand right sides of the upper part of the battery-mounting part 29, whichis the lower-end part of the housing 2. One of the hook grooves (notshown) is formed in the left motor housing 18, and the other hook groove39 is formed in the right motor housing 19. The hook 38 is attached by ascrew 40.

In addition, a strap 42 is attached to the rear part of thebattery-mounting part 29, which is the lower-end part of the housing 2.A loop-shaped strap-attaching loop is formed on one end of the strap 42,and that strap-attaching loop is looped around the lower rear screw—bosspart 22. The portion outside of the strap-attaching loop of the strap 42is a strap loop that has an elongated loop shape.

Furthermore, an operation panel 44 is provided on a front-upper part ofthe battery-mounting part 29 (an upper-surface part on the front side ofthe widened lower part of the handle part 6), which is the lower-endpart of the housing 2.

The operation panel 44 comprises: an impact-force switching button 46,which is electrically connected to the controller 33 and switches themagnitude of the impact force imparted by the hammer 16; anautomatic-speed-changing-mode switching button 48, which switcheswhether the automatic speed-changing mode is set, and a display part 49(FIG. 8).

The display part 49 comprises an impact-force display portion, whichdisplays the current impact force, a remaining-battery-charge displayportion, which displays the remaining charge of the battery 31, anautomatic-speed-changing-mode display portion, which displays whetherthe automatic speed-changing mode is set, and the like.

The motor 11 is a brushless motor (brushless DC motor) and is containedinside the motor housing composed of the left motor housing 18 and theright motor housing 19 (the rear part of the main-body part 4). Themotor 11 comprises, inside the left motor housing 18 and the right motorhousing 19: a circular-cylinder shaped stator 51, which is disposedinside a rib that extends inward; and a rotor 52 (inner rotor), which isdisposed in the interior of the stator 51.

The stator 51 comprises: a circular-cylinder shaped stator core 54, theaxial direction of which is in the front-rear direction and whichcomprises a plurality of (six) internal teeth that protrude inward; afront-insulating member 56 and a rear-insulating member 58, which areprovided on the front and rear of the stator core 54; and a plurality ofdrive coils 60, 60, . . . , the drive coils 60 being wound around theinternal teeth of the stator core 54 through (on) the front-insulatingmember 56 and the rear-insulating member 58. In addition, a sensorcircuit board 62 is fixed to the front-insulating member 56 by screws63, 63, . . . . Three magnetic sensors, which are not shown, are fixedto a front surface of the sensor circuit board 62. Furthermore, a totalof six coil-connection parts, which are not shown and serve as contactsthat electrically connect the sensor circuit board 62 with each of thedrive coils 60, is provided on a circumferential edge of a front surfaceof the front-insulating member 56. The coil-connection parts areelectrically connected to a terminal part 64, which protrudes downward;one end of each lead wire (not shown) is connected to the terminal part64, and the other end is connected to the controller 33.

The rotor 52 comprises: a motor shaft 66, which serves as a rotary shaft(rotor shaft); a circular-cylinder shaped rotor core 68, which isdisposed around the motor shaft 66; permanent magnets 70, 70, . . . ,which are tubular, are disposed on the outer side of the rotor core 68,and whose polarities alternate in the circumferential directions; and aplurality of sensor permanent magnets, which is not shown and isradially disposed on the front side of the permanent magnets 70, 70, . .. (i.e., on the sensor circuit board 62 side of the stator 51). Therotor core 68, the permanent magnets 70, and the sensor permanentmagnets constitute a rotor assembly. The permanent magnets 70, 70, . . .and the sensor permanent magnets in the rotor assembly can also beintegrally configured as four plate-shaped permanent magnets.

A tubular resin sleeve 72 is provided on the front side of the rotorcore 68 in the motor shaft 66. A motor front bearing 74, which isdisposed around the front part of the motor shaft 66, is providedforward of the sleeve 72. The motor front bearing 74 is mounted insidean opening of a rear part of a bearing retainer 75. A pinion gear 76 isfixed, integrally with the motor shaft 66, to a tip part of the motorshaft 66, which is the front side of the motor front bearing 74. On theother hand, a rear-end part of the motor shaft 66 is rotatably supportedby a motor rear bearing 77. The motor rear bearing 77 is held by aninterior center part of the rear cover 20.

The fan 10 is disposed in the vicinity of the rear part of the motorshaft 66. The fan 10 is a centrifugal fan having a plurality of bladesand is integrally fixed to the motor shaft 66 via a fan sleeve 78.

Air-exhaust ports 24, 24, . . . are located outward of the fan 10.

It is noted that the fan 10, a portion thereof, or the like can also beconfigured as a structural element of the motor 11.

The planetary-gear mechanism 12 comprises: a ring-shaped internal gear80, which has internal teeth; a plurality of planet gears 82, 82, . . ., each planet gear having external teeth that mesh with the internalgear 80; and pins 84, which are the shafts of the planet gears 82.

The internal gear 80 is non-rotatably (fixedly or immovably) mountedinside the opening of the rear-end part of the hammer case 21.

Each of the planet gears 82 is disposed inward of the internal gear 80.

Each of the pins 84 has a circular-column shape, in which the axialdirection is set in the front-rear direction.

The planet gears 82 are provided around the pins 84 in the state whereineach of the planet gears 82 is rotatable around its corresponding pin84.

The spindle 13 comprises a hollow discoidal part 90 at the rear partthereof. The discoidal part 90 protrudes outward (vertically andlaterally) with respect to the other portion of the spindle 13, and thediameter of the discoidal part 90 is larger than that of the otherportion. A rear end of the spring 14, which is formed in a ring shape,contacts the front surface of the discoidal part 90. In addition, aspindle bearing 94, which is mounted in a center part of the bearingretainer 75, is disposed on the outer side of the rear-end part of thespindle 13 in the state in which the rear-end part protrudes in acircular-cylinder shape rearward from a rear surface of the discoidalpart 90; the spindle 13 is rotatably supported.

The bearing retainer 75 has a circular-cylinder shaped inner surface ofa rear part, a circular-cylinder shaped inner surface of a center part,the diameter of which is larger than that of the circular-cylindershaped inner surface of the rear part, and a circular-cylinder shapedinner surface of the front part, the diameter of which is larger yet,and these inner surfaces are connected. A housing rib 96, which isformed in an inner part of the left motor housing 18 and the right motorhousing 19, is contained between the center part and the rear part ofthe bearing retainer 75. In addition, the bearing retainer 75 comprisesa retainer ring 98, which protrudes outward, between the center part andthe front part; the retainer ring 98 is interposed between the rear-endpart of the hammer case 21 and the front surface of the housing rib 96.Furthermore, the front part of the bearing retainer 75 is interposedbetween the inner side of the rear-end part of the hammer case 21 and anouter surface of the internal gear 80.

An inner diameter of the spindle bearing 94 is larger than an innerdiameter of the motor front bearing 74, which is held by the bearingretainer 75. In addition, a rear surface of the spindle bearing 94 isdisposed in a state wherein it is located forward of a front surface ofthe motor front bearing 74 and wherein the spindle bearing 94 and themotor front bearing 74 are shifted from one another in the front-reardirections. Thereby, the force transmitted from the spindle 13 to thespindle bearing 94 tends not to transmit to the motor front bearing 74,and therefore the motor front bearing 74, the motor 11, and the likehave a long life.

An inner hole 100 is formed in an inner part of the spindle 13. Thespindle 13, the front part of which is narrow and the rear part of whichis wider than the front part, passes through the inner hole 100. Therear part of the inner hole 100 is connected to the hollow part of thediscoidal part 90. The tip part of the motor shaft 66, the pinion gear76, etc. are contained in the rear part of the inner hole 100; the pins84, 84, . . . are fixed and the planet gears 82, 82, . . . are disposedin an inner part of the discoidal part 90; the pinion gear 76 and theplanet gears 82, 82, . . . mesh.

The hammer 16 has a hollow 101, which is hollowed in a tubular mannerforward from a rear surface of the hammer 16, a front part of the spring14 is contained in the hollow 101, and a ring-shaped front end of thespring 14 is disposed, via a plurality of spring balls 102, 102, . . .and a hammer washer 104, at the bottom (i.e., a front end) of the hollow101.

It should be noted that hammer balls 106, 106, which guide the hammer 16principally in the front-rear direction during impact, are interposedbetween the hammer 16 and a front part of the spindle 13.

The anvil 17, which is on the front side of the hammer 16, comprises achuck 112 on the circumference of the front part of the anvil 17.

The anvil 17 comprises a pair of extension parts 114, 114, which extendsin a radial direction, on the rear part of the anvil 17.

An anvil bearing 116, which rotatably supports the anvil 17 around itsaxis, is provided on the front side of the extension parts 114, 114. Theanvil bearing 116 is attached to an inner wall of a front-end part ofthe hammer case 21.

In addition, a rear hole, which is formed frontward, is provided ininner parts of the extension parts 114, 114, and is the center of therear-end part of the anvil 17; a protruding part 118, which is formed ina front-end part of the spindle 13, is contained in that rear hole. Therotation of the spindle 13 is transmitted to the anvil 17 via the hammer16, and thereby the elements from the hammer 16 and the spindle 13 tothe planetary-gear mechanism 12 constitute a motive-power transmissionmechanism that transmits motive power to the anvil 17. Thepower-transmission mechanism is contained inside the main-body part 4(the hammer case 21). The principal motive-power transmission directionof the power-transmission mechanism is a rotational direction in whichthe front-rear direction serves as the axis.

An anvil hole 120, which leads rearward from the front end of the anvil17, is formed in an interior of the anvil 17. The anvil hole 120receives the bit, which is not shown.

The chuck 112 fixes the bit that has been received in the anvil hole120.

The chuck 112 comprises a chuck sleeve 122, a chuck spring 124, a chuckwasher 126, a chuck-spring stop 127, and a plurality of chuck balls 128,128. The chuck sleeve 122 is a circular-cylinder shaped member andcomprises: a chuck front hole 130, the inner diameter of which is largerthan the outer diameter of the front part of the anvil 17 and which isformed extending from the front end to the center part; and a chuck-ballpressing part 132, the inner diameter of which is equal to the outerdiameter of the front part of the anvil 17 and which protrudes inwardwith respect to the chuck front hole 130.

The chuck spring 124 is contained in the chuck front hole 130.

The chuck washer 126 is disposed on the front side of the chuck spring124, which is inside the front-end part of the chuck front hole 130.

The chuck-spring stop 127 is a C-shaped member and is fixed to the outersurface of the tip part of the anvil 17 in the state in which thechuck-spring stop 127 is disposed on the front side of the chuck washer126. With regard to the chuck-spring stop 127, the chuck spring 124 ishoused inside the chuck front hole 130 via the chuck washer 126.

The chuck balls 128, 128 are disposed such that they are arranged alonga line in the radial direction of the anvil hole 120, protrude from theinterior of the anvil hole 120, and are capable of contacting thechuck-ball pressing part 132 of the chuck sleeve 122.

If the chuck sleeve 122 is pulled forward while receiving the elasticforce of the chuck spring 124, the chuck-ball pressing part 132separates from the chuck balls 128, the chuck balls 128 become capableof greatly moving to the outer side in the radial direction, the chuckballs 128 withdraw from the interior of the anvil hole 120 when the bitis inserted, the bit becomes capable or being inserted in the anvil hole120, and the bit becomes capable of being mounted. Furthermore, in thestate in which the rear part of the bit has been inserted, when thechuck sleeve 122 is returned rearward, the chuck-ball pressing part 132contacts the chuck balls 128, the chuck balls 128 push inward, and thebit is pressed and thereby fixed to the anvil 17.

Furthermore, a state-changing operation part 140, which is (located on)the lower part (portion) of the main-body part 4 (on the lower side ofthe hammer case 21, the bumper 27, etc.), is provided on the upper sideof the trigger 8 and forward of the forward/reverse switching lever 28.

The state-changing operation part 140 comprises: a state-switchingbutton 142, which serves as a state-switching switch that is capable ofbeing pressed by the user; and a state-switch transmitting part 144, inwhich a signal for switching among various states is transmitted basedon the operation (manipulation, pressing) of the state-switching button142.

The state-changing operation part 140 is contained in astate-changing-operation-part installation part 146, which is formed onthe lower part of the front-end part of the main-body part 4 in the leftmotor housing 18 and the right motor housing 19 in the state in whichthe front part of the state-switching button 142 is visible.

In addition, the state-changing operation part 140 is disposed in aportion in which the left motor housing 18 and the right motor housing19 overlap the hammer case 21 in the front-rear direction, and thestate-switching button 142 is disposed on the outer side of the hammercase 21.

The state-changing operation part 140 (the state-switch transmittingpart 144) is connected to the controller 33 by lead wires, which are notshown.

FIG. 8 shows the principal structural elements of a means of controllingthe impact driver 1.

The controller 33 comprises a control part 150, which controls variouselements.

The control part 150 is connected to the main-switch main-body part 9and controls the motor 11. The main-switch main-body part 9 turns ON andOFF in accordance with the amount by which the trigger 8 is pulled in;for example, the main-switch main-body part 9 turns ON if the trigger 8is pulled in by a first pull-in amount or greater and turns OFF if thetrigger 8 is pulled in by less than the first pull-in amount. Thecontrol part 150 turns the motor 11 ON and OFF in accordance with theON/OFF state of the main-switch main-body part 9.

In addition, the main-switch main-body part 9 transmits a signal inaccordance with the pull-in amount from the first pull-in amount to asecond pull-in amount at a further pulled-in position (e.g., a maximumpull-in position), and the control part 150 changes the rotational speedof the motor 11, in accordance with that signal (the pull-in amount ofthe trigger 8), by controlling the motor 11 such that the greater thepull-in amount, the higher the rotational speed. When the trigger 8 ismaximally pulled to the second pull-in amount, the control part 150drives the motor 11 such that it runs at maximum speed in accordancewith the current impact-force setting. Accordingly, the main switch 7can also be viewed as a rotational-speed-changing operation part thatchanges the rotational speed of the motor 11.

In addition, the control part 150 ascertains the switch states of theimpact-force switching button 46, the automatic-speed-changing-modeswitching button 48, etc. on the operation panel 44 and, in accordancewith those switch states, controls the drive of the motor 11,indications on the display part 49, and the like.

With each pressing of the impact-force switching button 46, the controlpart 150 sequentially switches the impact-force setting in four stages(levels or steps): “Maximum Speed,” “High,” “Medium,” and “Low.” If theimpact-force setting is “Maximum Speed,” then the control part 150 setsthe state in which the maximum speed during the drive of the motor 11 isthe maximum among the four stages, and thereby the impact force impartedby the hammer 16 is the maximum among the four stages. In addition, ifthe impact-force setting is “High,” “Medium,” or “Low,” then the controlpart 150 sets the state in which the maximum speed during the drive ofthe motor 11 is the second stage (level), the third stage (level), orthe fourth stage (level), respectively, of the four stages (levels orsteps), and thereby the impact force imparted by the hammer 16 is set tothe second stage, the third stage, or the fourth stage, respectively, ofthe four stages. In addition, the control part 150 causes the displaypart 49 (the impact-force display part) to function. For example, if theimpact-force setting is “Maximum Speed,” “High,” “Medium,” or “Low,”then the control part 150 turns ON four lamps, three lamps, two lamps,or one lamp, respectively, on the impact-force display part, whichcomprises four lamps (LEDs).

On the other hand, with each pressing of theautomatic-speed-changing-mode switching button 48, the control part 150alternately sets the automatic speed-changing mode or cancels that modeand sets a normal mode. If the mode is the automatic speed-changingmode, then, regardless of the current impact-force setting, the controlpart 150 automatically changes the speed of the motor 11 in accordancewith a program that is input in advance. In addition, the control part150 causes the display part 49 (the automatic-speed-changing-modedisplay part) to function. For example, on theautomatic-speed-changing-mode display part, which comprises one lamp(LED), the control part 150 turns the lamp ON if the mode is theautomatic speed-changing mode and turns the lamp OFF if the mode is thenormal mode.

Furthermore, the control part 150 ascertains the operation state of thestate-changing operation part 140 and controls the changing of the statein accordance with the various modes.

As shown in FIG. 9, in the same manner as the control in accordance withthe impact-force switching button 46, control related to thestate-changing operation part 140 is performed by the control part 150of the impact driver 1. It is noted that the process steps areabbreviated with “S” where appropriate.

That is, when the battery 31 is connected, the control part 150 sets thestate in which the maximum speed during drive of the motor 11 is themaximum speed among the four stages and thereby sets the impact forceimparted by the hammer 16 to “Maximum Speed,” which is the maximum amongthe four stages (51).

Then, if the state-switching button 142 is pressed and the state-switchtransmitting part 144 is switched (YES in S2), the control part 150 setsthe state in which the maximum speed during drive of the motor 11 is thesecond fastest among the four stages and thereby sets the impact forceimparted by the hammer 16 to “High,” which is the second stage from thehighest stage among the four stages (S3).

If the state-switching button 142 is pressed again and the state-switchtransmitting part 144 is switched again (YES in S4), then the controlpart 150 sets the state in which the maximum speed during drive of themotor 11 is the third fastest among the four stages and thereby sets theimpact force imparted by the hammer 16 to “Medium,” which is the secondstage from the lowest stage among the four stages (S5).

If the state-switching button 142 is then pressed once again and thestate-switch transmitting part 144 is switched once again (YES in S6),the control part 150 sets the state in which the maximum speed duringdrive of the motor 11 is the slowest among the four stages and therebysets the impact force imparted by the hammer 16 to “Low,” which is thefirst stage from the lowest stage among the four stages (S7).

Thereafter, the control part 150 awaits the pressing of thestate-switching button 142 (S8) and, if pressed, then the impact forceis once again set to “Maximum Speed” (returns to S1).

At the same time, the control part 150 displays the currently-selectedimpact force on the display part 49 (the impact-force display part), asdescribed above.

An operational example of the impact driver 1 of this type will now beexplained.

If the user grasps the handle part 6 and pulls the trigger 8, then themain-switch main-body part 9 switches, and thereby electric power issupplied from the battery 31 to the motor 11, which is driven at a speedin accordance with the pull-in amount of the trigger 8. Thereby, thetrigger 8 is a switch-operation part that switches the motor 11 ON andOFF via the main-switch main-body part 9 and thereby turns the motor 11ON and OFF; the trigger 8 and the main-switch main-body part 9constitute the main switch 7 of the motor 11.

The switching devices of the controller 33 switch the drive coils inaccordance with the rotational position of the rotor 52 ascertained bythe magnetic sensors of the sensor circuit board 62, and thereby therotor 52 (the motor shaft 66) rotates.

The fan 10 rotates owing to the rotation of the motor shaft 66 andexhausts air via the air-exhaust ports 24, 24, . . . , and thereby aflow of air from the air-suction ports 25, 25, . . . to the air-exhaustports 24 is generated. In addition to the motor 11, the other internalmechanisms of the impact driver 1 are cooled by the flow of the air.

Furthermore, the speed of the motor shaft 66 is reduced by theplanetary-gear mechanism 12 and the rotational force of the motor shaft66 is transmitted to the spindle 13; further, the rotational force ofthe spindle 13 is transmitted to the anvil 17 via the hammer 16.

In addition, if a torque of a prescribed threshold or greater isreceived at the anvil 17, then the spindle 13 guides the hammer 16 suchthat the hammer 16 oscillates forward and rearward (such that the hammer16 impacts). The elastic force of the spring 14 causes the hammer 16 toreturn to its original position after each impact.

Furthermore, the user can grasp the handle part 6 by a means other thanthe index finger and can press the state-changing operation part 140 onthe trigger 8 with the index finger; thereby, with each pressing of thestate-changing operation part 140, the control part 150 ascertains theswitching of the state-switch transmitting part 144 and sequentiallyswitches the impact-force setting.

The impact driver 1 described above comprises: the motor 11; themain-body part 4, in which the motor 11 is disposed; the handle part 6,which extends downward from the main-body part 4; the main switch 7,which is provided on the handle part 6 (the upper part) and switches themotor 11 ON and OFF; and the state-changing operation part 140, which is(located on) the front-end part of the lower part of the main-body part4, is provided upward of the main switch 7 and changes a rotationalstate (impact force) of the motor 11. Thereby, in addition to operatingthe state-changing operation part 140 with one hand while gripping theimpact driver 1 with the one hand, the user can operate thestate-changing operation part 140 with the index finger of that one handwhile gripping the handle part 6 by a means other than the index fingerof the one hand; further, in the impact driver 1, it becomes possible toswitch the impact force by operating the state-changing operation part140 with one hand alone, and therefore ease of operation is much moresatisfactory.

In addition, the state-changing operation part 140 is disposed forwardof the main switch 7. Thereby, operation of the state-switching button142 is performed with a forward finger, such as the index finger, whilethe handle part 6 is held with one hand, and therefore operation is mucheasier to perform.

In addition, the impact driver 1 comprises: the motor 11; the main-bodypart 4, in which the motor 11 is disposed; the handle part 6, whichextends downward from the main-body part 4; the main switch 7, which isprovided on the upper part of the handle part 6 and switches the motor11 ON and OFF; and the state-switching button 142, which is (located on)the front-end part of the main-body part 4, is provided upward of themain switch 7 and switches a rotational state (the impact force) of themotor 11. Thereby, in the impact driver 1, it becomes possible to switchthe impact force by operating the state-switching button 142 on thefront-end part with one hand alone, and therefore ease of operation ismuch more satisfactory.

Furthermore, the state-switching button 142 of the impact driver 1 isprovided on the lower part of the main-body part 4. Thereby, thestate-switching button 142 is disposed at a location adjacent the handlepart 6, and thus the operation of the state-switching button 142 whileholding the handle part 6 with one hand is much easier.

It is noted that the embodiments of the present teachings are notlimited to the above-mentioned first embodiment; for example, the firstembodiment includes, where appropriate, the following modified examples.

The main switch, the trigger, etc. may be disposed at a location otherthan the upper-end part, which is the upper part, of the handle part,and the state-changing operation part may be provided on the upper-endpart of the handle part. Even in such an embodiment, the state-changingoperation part can be made easy to operate with one hand whilemaintaining ease of operation of the main switch.

The number of stages (levels or steps) of the impact force can beincreased or decreased. The switching of the impact force may be suchthat it becomes stronger in order from “Low.” The switching of theimpact force and the switching of the automatic speed-changing mode maybe merged; for example, switching may be performed in order from“Maximum Speed,” “High,” “Medium,” “Low,” and automatic speed-changingmode.

At least one of the various display parts on the operation panel may beomitted, other types of display parts may be added, the locations of thedisplay parts, the buttons, and the like may be changed to locationsother than the operation panel, and so on. The automatic speed-changingmode and the switching button thereof may be omitted. Modes other thanthe automatic speed-changing mode may be provided.

The operation panel, the impact-force switching button, or the like maybe omitted, and the impact force may be changed by the state-changingoperation part alone.

The state-changing operation part may be a state-switching switch, suchas a state-switching button or a state-switching lever, that switchesthe stage of the impact force or may be a state-changing dial or thelike that changes the impact force without stages (steps), i.e.continuously. In addition, the state-changing operation part may be atouch panel that switches the stage of the impact force or changes theimpact force without stages or continuously.

Instead of switching (level changing) based upon the pressing of abutton switch, the various switches, including the state-switchingbutton, and the transmitting part (the switch main-body part) thereofcan be of some other type, such as a toggle switch operated by a lever,a rocker switch, a DIP switch, a switch that switches based on a contactsensor, and the like. Switches of types other than one in which atrigger is pulled may be used as the main switch. The main switch may bea switch that switches the motor only ON and OFF without changing therotational speed of the motor. The switches, dials, etc. and thetransmitting part (the switch main-body part) may be integrated. Thesignal in accordance with the switches, the dials, etc. may be theresistance value of a variable resistor, or the like.

A motor-control part that controls the motor and a switch-control partthat controls the switches may be implemented separately by hardware.

In the planetary-gear mechanism, instead of inserting the pins in thecarrier or in addition thereto, the pins may be inserted into holes ofprojections or tabs may be latched to one another. In addition, theholes into which the pins are inserted may be holes having a bottom,i.e. a blind hole.

The planetary-gear mechanism may be modified to some otherspeed-reducing mechanism or may be omitted.

The motor may be an outer-rotor type in which the rotor is disposed onthe outer side of the stator. In addition, the motor may be a motorother than a brushless motor. The six switching devices may be disposedon the sensor circuit board instead of the controller. In addition, thenumber of the switching devices, the drive coils, the sensor permanentmagnets, the magnetic sensors, etc. can be increased or decreased whereappropriate. The sensor circuit board can also be screwed to therear-insulating member in the state in which the sensor circuit board isdisposed rearward of the rear-insulating member.

One or two or more intermediate shafts may be interposed between themotor shaft and the anvil.

The battery may be any lithium-ion battery of 10.8 V, 18 V (max. 20 V),18 V, 25.2 V, 28 V, 36 V, etc. or of a voltage that is less than 10.8 Vor greater than 36 V; in addition, other types of batteries may be used.

The number of sections of the housing, the number of planet gearsinstalled, the number of stages of the speed-increasing mechanism, thenumber of the air-suction/air-exhaust ports, and the like can beincreased or decreased, and the number, placement, material, size, andtype of the various members and portions can be modified whereappropriate.

The present teachings can also be adapted to a rechargeable driver drillor a vibration-driver drill by utilizing a gear case, omitting thehammer and the anvil, further disposing a speed-reducing-mechanism partsuch as, for example, a two-stage planetary-gear mechanism, making theoutput shaft of the speed-reducing-mechanism part protrude forward fromthe gear case, and fixing the tool-accessory holding part (tool holderor chuck), which holds the tool accessory, to the front part of theoutput shaft.

In addition, the present teachings can also be adapted to a rechargeableangle power tool, wherein the direction of the output shaft (thetool-accessory retaining part) differs (by substantially 90°) from theaxial direction (the direction of the motor shaft of the motor, thetransmission direction of the mechanism that transmits that rotationalforce, and the like).

Furthermore, the present teachings can also be adapted to: otherrechargeable power tools, such as an impact wrench, a screwdriver, ahammer drill, a reciprocating saw, or the like; a power tool connectedto a commercial power supply; a gardening tool, such as a cleaner, ablower, or a gardening trimmer; and the like.

Second Embodiment

FIG. 10 is an oblique view, viewed from the front, of an impact driver201 according to a second embodiment of the present teachings; FIG. 11is a front view of the impact driver 201; FIG. 12 is a right view of theimpact driver 201; FIG. 13 is an enlarged view of the upper part of thecenter longitudinal-cross-sectional view of the impact driver 201; FIG.14 is a center transverse-cross-sectional view of a main-body part 204of the impact driver 201; and FIG. 15 is a cross-sectional view takenalong line B-B in FIG. 12.

The impact driver 201 is configured similarly to the impact driver 1 ofthe first embodiment, with the exception of the configuration of thefront part of the main-body part. Hereinbelow, structural elementssimilar to those in the first embodiment are assigned the same symbols(reference numerals) as in the first embodiment, and explanationsthereof are omitted where appropriate.

A state-changing operation part 240, which is configured similarly tothe state-changing operation part 140 of the first embodiment, isdisposed on the front-end part of the lower part of the main-body part204 of the impact driver 201. The state-changing operation part 240comprises a state-switching button 242, which serves as astate-switching switch, and a state-switch transmitting part 243.

It is noted that screws 208 for fixing the rear cover 20, which do notappear in the drawings related to the first embodiment, do appear inFIG. 14.

A pair of lights 210 is provided on a front-end part of a left housing218 and a front-end part of a right housing 219 (the rear side of thecover 26) of the housing 202, which are the right and left sides of thefront part of the main-body part 204 of the impact driver 201.Light-installation parts 209, which protrude outward in the left-rightdirection, constitute the installation parts of the lights 210 on thehousing 202.

Each light 210 comprises an LED 212, which is a light-emitting member,and a light circuit board 214, on which the LED 212 is installed.

Each LED 212 comprises a light-emitting part and terminal parts, and thelight-emitting part is visible frontward from the housing 202. Theterminal parts of each LED 212 are electrically connected to thecontroller 33 via the corresponding light circuit board 214.

The lights 210 (the LEDs 212) are controlled by the controller 33 (thecontrol part 150) as shown in, for example, FIG. 16A.

That is, as shown in FIG. 16A (light switching), when the battery 31 isconnected, the control part 150 sets the lamp ON/OFF state of the lights210 to OFF, and thereby causes the LEDs 212 to not emit light (S11).

If the state-switching button 242 is then pressed and the state-switchtransmitting part 243 is switched (YES in S12), the control part 150sets the lamp ON/OFF state of the lights 210 to ON, electric power issupplied to the LEDs 212 via the light circuit boards 214, and the LEDs212 are caused to emit light (S13).

Thereafter, the control part 150 awaits the pressing of thestate-switching button 242 (S14) and, if pressed (YES), then the lampON/OFF state of the lights 210 once again becomes ON (return to S11).

Compared with the operation panel 44 of the first embodiment, it isnoted that the operation panel 244 of the impact driver 201 isconfigured with the addition of a light-switching button 247. When thereis another input to the light-switching button 247, the control part 150switches the lamp ON/OFF state to a state other than the current state.A display part related to the lamp ON/OFF state of the lights 210 may beprovided on the operation panel 244.

In addition, as shown in FIG. 16B (forward/reverse-rotation switching),if the pressing of the state-switching button 242 continues for aprescribed time (e.g., 2 s) or longer (a long press), then the controlpart 150 switches the switch-reception mode to a mode according to theswitching of the state of the rotational direction of the motor 11. Itis noted that, instead of or in addition to a long press of thestate-switching button 242, the switching of the switch-reception modemay be a simultaneous pressing of the state-switching button 242 and thetrigger 8, a double click of the state-switching button 242 (multipleinputs within a prescribed time, e.g., 1 s), or a combination thereof.The switching of the switch-reception mode may be performed by adedicated switch.

The switch-reception mode differentiates which state is switched by thestate-switching button 242, and includes: a light-switching mode, whichswitches the lamp ON/OFF state of the lights 210 as shown in FIG. 16A; aforward/reverse-rotation switching mode, which switches the rotationaldirection of the motor 11 to a forward-rotation state (here, clockwiseviewed from the front) or a reverse-rotation state (counterclockwise),as shown in FIG. 16B; or an impact-force switching mode, which switchesthe impact force, as shown in FIG. 9.

In the control part 150 of the impact driver 201, when the battery 31 isconnected (initially), the switch-reception mode is set to thelight-switching mode; and with each subsequent long press of thestate-switching button 242, the mode sequentially switches to theforward/reverse-rotation switching mode, the impact-force switchingmode, and then returns to the light-switching mode. It is noted that thetransitions of the switch-reception mode may be in an order other thanthat above, some of the switch-reception modes may be omitted, and othertypes of switch-reception modes may be added. Furthermore, aswitch-reception-mode-display part that displays (a symbol correspondingto) the type of the current switch-reception mode may be provided on theoperation panel 244 or the like.

In the forward/reverse-rotation switching mode, the control part 150sets the rotational direction of the motor 11, which is theforward-rotation state in the initial state (S21), and, by the pressingof the state-switching button 242 (YES in S22), switches to thereverse-rotation state (S23).

Thereafter, the control part 150 awaits the pressing of thestate-switching button 242 (S24) and, if pressed (YES), then the stateof the rotational direction of the motor 11 becomes forward rotation(returns to S21).

The control part 150 switches the forward/reverse switching lever 28 inaccordance with the current state of the rotational direction.

The impact driver 201 as described above comprises: the motor 11; themain-body part 204, in which the motor 11 is disposed; the handle part6, which extends downward from the main-body part 204; the main switch7, which is provided on (the upper part of) the handle part 6 andswitches the motor 11 ON and OFF; the lights 210, which radiate light;and the state-changing operation part 240, which is (located on) thelower part of the main-body part 204, is provided upward of the mainswitch 7, and changes the lamp ON/OFF state of the lights 210. Thereby,the user can change the lamp ON/OFF state of the lights 210 by operatingthe state-changing operation part 240 while holding the impact driver201 with one hand, and thus an impact driver 201 that excels in ease ofoperation is provided.

In addition, the state-changing operation part 240 is disposed forwardof the main switch 7. Thereby, the state-switching button 242 can beoperated with a forward finger while the handle part 6 is held with onehand, and thus operation is much easier.

In addition, the impact driver 201 comprises: the motor 11; themain-body part 204, in which the motor 11 is disposed; the handle part6, which extends downward from the main-body part 204; the main switch7, which is provided on the handle part 6 and switches the motor 11 ONand OFF; the lights 210, which radiate light; and the state-switchingbutton 242, which is the front-end part of the main-body part 204, isprovided upward of the main switch 7, and switches the lamp ON/OFF stateof the lights 210. Thereby, the operation of turning the lights 210 ONand OFF is easy.

Furthermore, the state-switching button 242 of the impact driver 1 isprovided on the lower part of the main-body part 4. Thereby, thestate-switching button 242 is disposed at a location adjacent the handlepart 6 and therefore the operation (manipulation) of the state-switchingbutton 242 while holding the handle part 6 with one hand is much easier.

It is noted that the above-mentioned second embodiment includes, whereappropriate, modified examples similar to those of the first embodiment.

For example, the state-changing operation part may be disposed on thefront side of the upper-end part of the handle part, and the trigger maybe provided on the lower side thereof.

In addition, the light circuit boards do not have to be provided, thenumber of the lights installed may be increased or decreased, and thelights may be installed at other locations.

The forward/reverse switching lever, the light-switching button, etc.may be omitted. The state-changing operation part serves as acontinuous-change operating means, such as a dial, and the brightness ofthe light may be changed without stages or continuously.

Third Embodiment

FIG. 17 is an oblique view, viewed from the rear, of an impact driver301 according to a third embodiment of the present teachings; FIG. 18 isa rear view of the impact driver 301; FIG. 19 is a right view of theimpact driver 301; FIG. 20 is an enlarged view of the upper part of thecenter longitudinal-cross-sectional view of the impact driver 301; FIG.21 is a center transverse-cross-sectional view of a main-body part 304of the impact driver 301; and FIG. 22 is a cross-sectional view takenalong line C-C in FIG. 19.

The impact driver 301 is configured similarly to the impact driver 1 ofthe first embodiment, with the exception of the configuration of themain-body part (the state-changing operation part). Hereinbelow,structural elements similar to those of the first embodiment areassigned the same symbols (reference numerals) as in first embodiment,and explanations thereof are omitted where appropriate.

A state-changing operation part 340 of the impact driver 301 is disposedon a rear-end lower part of the main-body part 304.

The state-changing operation part 340 is disposed inside astate-changing-operation-part installation part 346, which is formeddownward of the fan 10. The state-changing-operation-part installationpart 346 is formed on a lower-end part of a rear cover 320 of a housing302 and between a left housing 318 and a right housing 319.

A state-switch transmitting part 344 of the state-changing operationpart 340 is housed inside the housing 302, and a rear surface of astate-switching button 342, which serves as a state-switching switch, isvisible from the rear surface of the housing 302.

If the control part 150 ascertains that an input has been made to thestate-changing operation part 340, then the control part 150sequentially switches the impact force.

The impact driver 301 described above comprises: the motor 11; themain-body part 304, in which the motor 11 is disposed; the handle part6, which extends downward from the main-body part 304; the main switch7, which is provided on the handle part 6 and switches the motor 11 ONand OFF; and the state-changing operation part 340, which is (locatedon) the rear-end part of the lower part of the main-body part 304, isprovided upward of the main switch 7, and changes a rotational state(the impact force) of the motor 11. Thereby, the user, while holding thehandle part 6 in the palm of one hand with all fingers except the thumb,can switch the state-changing operation part 340 with that thumb; or,the trigger 8 side can be set downward and the user, while supportingthe handle part 6 with one hand except the thumb, can switch thestate-changing operation part 340 with that thumb; further, in theimpact driver 301, the impact force is switchable by an input being madeto the state-changing operation part 340 with one hand alone, andtherefore ease of operation is much more satisfactory.

In addition, the impact driver 301 comprises: the motor 11; themain-body part 304, in which the motor 11 is disposed; the handle part6, which extends downward from the main-body part 304; the main switch7, which is provided on the handle part 6 and switches the motor 11 ONand OFF; and the state-switching button 342, which is (located on) therear-end part of the main-body part 304, is provided upward of the mainswitch 7, and switches a rotational state (the impact force) of themotor 11. Thereby, in the impact driver 301, the impact force isswitchable by the operation of the state-switching button 342 on thefront-end part with one hand alone, and therefore ease of operation ismuch more satisfactory.

Furthermore, the state-switching button 342 of the impact driver 301 isprovided on the lower part of the main-body part 304. Thereby, thestate-switching button 342 is disposed at a location adjacent the handlepart 6, and the operation of the state-switching button 342 while thehandle part 6 is being held with one hand alone is much easier.

It is noted that the above-mentioned third embodiment includes, whereappropriate, modified examples similar to those of the first embodimentand the second embodiment.

For example, the state-changing operation part may be provided on therear side of the upper-end part of the handle part.

In addition, the state-changing-operation-part installation part may bedisposed inside the rear cover, inside the space from the left housingto the right housing, or the like.

In the third embodiment, the lights may be disposed as in the secondembodiment, and other input-reception modes may be set and switched. Thelights may be provided on the lower part of the front-end part of themain-body part (at the location of the state-changing-operation-partinstallation part according to the first embodiment).

A plurality of the state-changing operation parts may be provided wherethe state-changing operation part is located in the third embodiment,where the state-changing operation part is located in the firstembodiment, etc.

Fourth Embodiment

FIG. 23 is an oblique view, viewed from the front, of an impact driver401 according to a fourth embodiment of the present teachings; FIG. 24is a front view of the impact driver 401; FIG. 25 is a right view of theimpact driver 401; FIG. 26 is an enlarged view of an upper part of thecenter longitudinal-cross-sectional view of the impact driver 401; FIG.27 is a transverse-cross-sectional view of the section between amain-body part 404 and the trigger 8 of the impact driver 401; and FIG.28 is a cross-sectional view taken along line D-D in FIG. 25.

The impact driver 401 is configured similarly to the first embodiment,with the exception of the configuration of the front-lower part (thestate-changing operation part) of the main-body part. Hereinbelow,structural elements similar to those of the first embodiment areassigned the same symbols (reference numerals) as in the firstembodiment, and explanations thereof are omitted where appropriate.

A state-changing operation part 440 of the impact driver 401 is disposedon a front-end lower part of the main-body part 404 such that astate-switching button 442, which serves as the state-switching switch,is visible on the right side.

The state-changing operation part 440 is installed in a housing 402 (aleft housing 418 and a right housing 419) inside astate-changing-operation-part installation part 446, which is formedsuch that it is open on (to) the right side.

A state-switch transmitting part 444 of the state-changing operationpart 440 is housed inside the housing 402, and the state-switchingbutton 442 is visible from a right surface of the housing 402.

If the control part 150 ascertains that the state-changing operationpart 440 has been switched, then the control part 150 sequentiallyswitches the magnitude of the impact force.

The impact driver 401 described above comprises: the motor 11; themain-body part 404, in which the motor 11 is disposed; the handle part6, which extends downward from the main-body part 404; the main switch7, which is provided on the handle part 6 and switches the motor 11 ONand OFF; and the state-changing operation part 440, which is (locatedon) the rear-end part of the lower part of the main-body part 404, isprovided upward of the main switch 7, and changes a rotational state(the impact force) of the motor 11. Thereby, the user, while holding theimpact driver 401 with one hand in the state in which the chuck 112 isoriented toward the inner side, can operate the state-changing operationpart 440 of the front-end lower part of the main-body part 404 with theother hand and can operate the state-changing operation part 440 toswitch the impact force even if the other hand is not deeply inserted onthe side of the impact driver 401; thus, ease of operation is much moresatisfactory.

In addition, the impact driver 401 comprises: the motor 11; themain-body part 404, in which the motor 11 is disposed; the handle part6, which extends downward from the main-body part 404; the main switch7, which is provided on the upper part of the handle part 6 and switchesthe drive of the motor 11; and the state-switching button 442, which is(located on) the right side of the front-end part of the main-body part404, is provided upward of the main switch 7, and switches a rotationalstate (the impact force) according to the motor 11. Thereby, in theimpact driver 401, the impact force is switchable by operating(manipulating, pressing) the state-switching button 442 on the rightside of the front-end part, and thus ease of operation is much moresatisfactory.

Furthermore, the state-switching button 442 of the impact driver 401 isprovided on the lower part of the main-body part 404. Thereby, thestate-switching button 442 is disposed at a location adjacent the handlepart 6, and the operation of the state-switching button 442 while thehandle part 6 is being held is much easier.

It is noted that the above-mentioned fourth embodiment includes, whereappropriate, modified examples similar to those of the first to thirdembodiments.

For example, in the fourth embodiment, the lights may be provided as inthe second embodiment, and the changing of the switch-reception mode maybe performed or the switching of the lamp ON/OFF state and the switchingof the rotational-direction state may be performed.

Furthermore, the state-changing operation part may be provided on theleft side of the main-body part or may be provided sideward of theupper-end part of the handle part.

In the fourth embodiment, the state-switching buttons of the firstembodiment, the third embodiment, and the modified examples thereof maybe provided in combination. A plurality of the state-switching buttonsmay be provided in the singular state-switch transmitting part.

Representative, non-limiting examples of the present invention weredescribed above in detail with reference to the attached drawings. Thisdetailed description is merely intended to teach a person of skill inthe art further details for practicing preferred aspects of the presentteachings and is not intended to limit the scope of the invention.Furthermore, each of the additional features and teachings disclosedabove may be utilized separately or in conjunction with other featuresand teachings to provide improved power tools.

Moreover, combinations of features and steps disclosed in the abovedetailed description may not be necessary to practice the invention inthe broadest sense, and are instead taught merely to particularlydescribe representative examples of the invention. Furthermore, variousfeatures of the above-described representative examples, as well as thevarious independent and dependent claims below, may be combined in waysthat are not specifically and explicitly enumerated in order to provideadditional useful embodiments of the present teachings.

All features disclosed in the description and/or the claims are intendedto be disclosed separately and independently from each other for thepurpose of original written disclosure, as well as for the purpose ofrestricting the claimed subject matter, independent of the compositionsof the features in the embodiments and/or the claims. In addition, allvalue ranges or indications of groups of entities are intended todisclose every possible intermediate value or intermediate entity forthe purpose of original written disclosure, as well as for the purposeof restricting the claimed subject matter.

Although some aspects of the present disclosure have been described inthe context of a device, it is to be understood that these aspects alsorepresent a description of a corresponding method, so that each block orcomponent of a device, such as the controller 33 or control part 150 isalso understood as a corresponding method step or as a feature of amethod step. In an analogous manner, aspects which have been describedin the context of or as a method step also represent a description of acorresponding block or detail or feature of a corresponding device, suchas the controller 33 or control part 150.

Depending on certain implementation requirements, exemplary embodimentsof the controller 33 or control part 150 of the present disclosure maybe implemented in hardware and/or in software. The implementation can beconfigured using a digital storage medium, for example one or more of aROM, a PROM, an EPROM, an EEPROM or a flash memory, on whichelectronically readable control signals (program code) are stored, whichinteract or can interact with a programmable hardware component suchthat the respective method is performed.

A programmable hardware component can be formed by a processor, acomputer processor (CPU=central processing unit), anapplication-specific integrated circuit (ASIC), an integrated circuit(IC), a computer, a system-on-a-chip (SOC), a programmable logicelement, or a field programmable gate array (FGPA) including amicroprocessor.

The digital storage medium can therefore be machine- or computerreadable. Some exemplary embodiments thus comprise a data carrier ornon-transient computer readable medium which includes electronicallyreadable control signals which are capable of interacting with aprogrammable computer system or a programmable hardware component suchthat one of the methods described herein is performed. An exemplaryembodiment is thus a data carrier (or a digital storage medium or anon-transient computer-readable medium) on which the program forperforming one of the methods described herein is recorded.

In general, exemplary embodiments of the present disclosure, inparticular the controller 33 or control part 150, are implemented as aprogram, firmware, computer program, or computer program productincluding a program, or as data, wherein the program code or the data isoperative to perform one of the methods if the program runs on aprocessor or a programmable hardware component. The program code or thedata can for example also be stored on a machine-readable carrier ordata carrier. The program code or the data can be, among other things,source code, machine code, bytecode or another intermediate code.

A program according to an exemplary embodiment can implement one of themethods during its performing, for example, such that the program readsstorage locations or writes one or more data elements into these storagelocations, wherein switching operations or other operations are inducedin transistor structures, in amplifier structures, or in otherelectrical, optical, magnetic components, or components based on anotherfunctional principle. Correspondingly, data, values, sensor values, orother program information can be captured, determined, or measured byreading a storage location. By reading one or more storage locations, aprogram can therefore capture, determine or measure sizes, values,variable, and other information, as well as cause, induce, or perform anaction by writing in one or more storage locations, as well as controlother apparatuses, machines, and components, and thus for example alsoperform complex processes using the electric motor 11 and othermechanical structures of the power tool.

Therefore, although some aspects of the controller 33 or control part150 have been identified as “parts” or “units” or “steps”, it isunderstood that such parts or units or steps need not be physicallyseparate or distinct electrical components, but rather may be differentblocks of program code that are executed by the same hardware component,e.g., one or more microprocessors.

EXPLANATION OF THE REFERENCE NUMBERS

-   1, 201, 301, 401 Impact driver (power tool)-   4, 204, 304, 404 Main-body part-   6 Handle part-   7 Main switch-   140, 240, 340, 440 State-changing operation part-   142, 242, 342, 442 State-switching button (state-switching switch)-   210 Light

The invention claimed is:
 1. A power tool comprising: a main housing; amotor disposed in the main housing; a controller configured to controloperation of the motor; a handle extending obliquely from the mainhousing; a trigger that is depressible to energize the motor, thetrigger being disposed on the handle between a first portion of thehandle that connects to the main housing and a second portion of thehandle that is remote from the first portion of the handle; a firstbutton located on the main housing adjacent to the handle or on thefirst portion of the handle, the first button being configured todepress a first switch that is electrically connected with thecontroller and being disposed in a plane that intersects the trigger,the first portion of the handle and the second portion of the handle soas to be operable by a finger of a user's hand while the user isgripping the handle, the first button being pressable to cycle throughand manually select one impact force setting from among a plurality ofstored impact force settings solely by a single push of the firstbutton; and a second button located on the second portion of the handle,the second button being configured to depress a second switch that iselectrically connected with the controller and being pressable to cyclethrough and manually select one impact force setting from among theplurality of stored impact force settings.
 2. The power tool accordingto claim 1, wherein the trigger and the first switch are rearwardlydepressible in parallel in a front-rear direction of the main housing.3. The power tool according to claim 1, wherein the controller isconfigured to control the operation of the motor according to thecurrently-selected impact force setting.
 4. The power tool according toclaim 1, wherein the first button and the trigger are arranged such thatboth the first button and the trigger are alternately pressable with anindex finger of a hand that is grasping the handle with fingers otherthan the index finger of the same hand.
 5. The power tool according toclaim 1, further comprising: a forward/reverse switching lever supportedon the main housing, the forward/reverse switching lever being pressableto switch the rotational direction of the motor; a right housing halfand a left housing half that are joined together to constitute the mainhousing and the handle; and a screw that fixes the right housing halfand the left housing half; wherein the screw is disposed between theforward/reverse switching lever and the first button.
 6. The power toolaccording to claim 1, further comprising a third button located on thesecond portion of the handle adjacent to the second button, the thirdbutton being pressable to select one automatic-speed-changing mode froma plurality of stored automatic-speed-changing modes that eachautomatically change the rotational speed of the motor during operationof the power tool, irrespective of the currently-selected impact forcesetting, in accordance with a program stored in the controller.
 7. Thepower tool according to claim 1, further comprising: an operationalpanel located on the second portion of the handle; wherein a displaypart configured to display the currently-selected impact force settingis disposed on the operational panel; and the second button is disposedon the operational panel adjacent to the display part.
 8. The power toolaccording to claim 1, further comprising a third button disposed on thesecond portion of the handle and being pressable to generate a signalthat is transmitted to the controller to select oneautomatic-speed-changing mode from a plurality ofautomatic-speed-changing modes that each automatically change therotational speed of the motor during operation of the power tool,irrespective of the currently-selected impact force setting, or tocancel the selection of a previously selected automatic-speed-changingmode, the controller having a stored program that, when executed,automatically changes the rotational speed of the motor during operationof the power tool in accordance with the currently-selectedautomatic-speed-changing mode.
 9. A power tool comprising: a mainhousing; a motor disposed in the main housing; a controller configuredto control operation of the motor; a handle extending obliquely from themain housing; a trigger that is depressible to energize the motor, thetrigger being disposed on the handle between a first portion of thehandle that connects to the main housing and a second portion of thehandle that is remote from the first portion of the handle; animpact-force pushbutton switch located in the second portion of thehandle, the impact-force pushbutton switch being electrically connectedwith the controller and configured to manually select one impact forcesetting from among a plurality of stored impact force settings with eachpressing of the impact-force pushbutton switch; anautomatic-speed-changing mode pushbutton switch located in the secondportion of the handle and configured to output a signal to thecontroller that selects one automatic-speed-changing mode from aplurality of automatic-speed-changing modes or cancels the selection ofa previously selected automatic-speed-changing mode; and a state-settingpushbutton switch located on the main housing adjacent to the handle oron the first portion of the handle and being disposed in a plane thatintersects the trigger, the first portion of the handle and the secondportion of the handle so as to be operable by a finger of a user's handwhile the user is gripping the handle, the state-setting pushbuttonswitch being pressable to cycle through the plurality of stored impactforce settings in response to each press of the state-setting pushbuttonswitch.
 10. The power tool according to claim 9, wherein thestate-setting pushbutton switch and the trigger are arranged such thatboth the state-setting pushbutton switch and the trigger are alternatelypressable with an index finger of a hand that is grasping the handlewith fingers other than the index finger of the same hand.
 11. The powertool according to claim 10, further comprising: a forward/reverseswitching lever supported on the main housing, the forward/reverseswitching lever being pressable to switch the rotational direction ofthe motor; a right housing half and a left housing half that are joinedtogether to constitute the main housing and the handle; and a screw thatfixes the right housing half and the left housing half; wherein thescrew is disposed between the forward/reverse switching lever and thestate-setting pushbutton button.
 12. A power tool comprising: a motor; aspindle operably coupled to the motor and extending in a front-reardirection; a main housing that accommodates the motor and is elongatedin the front-rear direction; a handle portion extending from the mainhousing obliquely with respect to the front-rear direction; a switchmain-body part provided in an upper portion of the handle portion; atrigger provided forward of the switch main-body part in the front-reardirection and being depressible rearward in the front-rear direction tochange a state of the switch main-body part; a state-switch transmittingpart provided in the main housing or in the handle portion between thetrigger and the spindle in an up-down direction that is perpendicular tothe front-rear direction; a state-switching button provided forward ofthe state-switch transmitting part in the front-rear direction and beingdepressible rearward in the front-rear direction to change a switchstate of the state-switch transmitting part; and a controllerelectrically connected to the switch main-body part and to thestate-switch transmitting part, the controller being configured tochange a currently-selected impact force that is applied to the spindlein response to each change of the switch state of the state-switchingbutton.
 13. The power tool according to claim 12, further comprisingfirst and second lights respectively disposed on left and right sides ofthe main housing in a left-right direction that is perpendicular to thefront-rear direction and to the up-down direction.
 14. The power toolaccording to claim 12, further comprising: a ring-shaped bumper disposedaround the spindle, wherein a front end of the bumper in the front-reardirection is located forward of a front end of the state-switchingbutton in the front-rear direction.
 15. The power tool according toclaim 12, further comprising: at least one display part located on alower portion of the handle portion below the trigger in the up-downdirection, wherein the at least one display part is electricallyconnected to the controller and is configured to display thecurrently-selected impact force.
 16. The power tool according to claim15, further comprising: an operation panel that includes an impact-forceswitching button electrically connected to the controller and configuredto switch the currently-selected impact force in response to eachpressing of the impact-force switching button; wherein: the operationpanel is located on the lower portion of the handle below the trigger inthe up-down direction and includes the at least one display part; andthe spindle, the state-switching button, and the trigger are intersectedby a common plane extending in the up-down direction.
 17. The power toolaccording to claim 16, wherein the controller is configured to controlthe operation of the motor according to the currently-selected impactforce.
 18. The power tool according to claim 17, wherein thestate-switching button and the trigger are arranged such that both thestate-switching button and the trigger are alternately pressable with anindex finger of a hand that is grasping the handle with fingers otherthan the index finger of the same hand.
 19. The power tool according toclaim 18, further comprising: an automatic-speed-changing-mode switchingbutton configured to select an automatic speed-changing mode that isexecuted by the controller to control a rotational output speed of themotor during operation; wherein: the automatic-speed-changing-modeswitching button is located on the operational panel; and theautomatic-speed-changing-mode switching button is pressable to generatea signal that is transmitted to the controller to select theautomatic-speed-changing mode from a plurality ofautomatic-speed-changing modes that each automatically change therotational output speed of the motor during operation of the power tool,irrespective of the currently-selected impact force, or to cancel theselection of a previously selected automatic-speed-changing mode, thecontroller having a stored program that, when executed, automaticallychanges the rotational output speed of the motor during operation of thepower tool in accordance with the currently-selectedautomatic-speed-changing mode.
 20. The power tool according to claim 19,further comprising: first and second lights respectively disposed onleft and right sides of the main housing in a left-right direction thatis perpendicular to the front-rear direction and to the up-downdirection; a ring-shaped bumper disposed around the spindle forward ofthe first and second lights in the front-rear direction; aforward/reverse switching lever supported on the main housing, theforward/reverse switching lever being pressable to switch the rotationaldirection of the motor; a right housing half and a left housing halfthat are joined together to constitute the main housing and the handleportion; and a screw that fixes the right housing half and the lefthousing half; wherein the screw is disposed between the forward/reverseswitching lever and the state-switching button; and a front end of thebumper in the front-rear direction is located forward of a front end ofthe state-switching button in the front-rear direction.
 21. A power toolcomprising: a motor housing; a hammer case disposed on a front side ofthe motor housing; a handle part disposed on a lower side of the motorhousing; a brushless motor housed in the motor housing; a hammerdisposed inside the hammer case and configured to be rotated by thebrushless motor; an anvil configured to be impacted in a rotationaldirection by the hammer; a battery-mounting part disposed below thehandle part; a first switch provided at an upper-end portion of thehandle part and configured to control energization of the brushlessmotor; a trigger disposed on a front side of the first switch, thetrigger being movable in a rearward direction to depress the firstswitch; a second switch provided immediately below the anvil and abovethe trigger and disposed inside of a lower-end portion of the motorhousing, the second switch being configured to change a rotational speedmode of the brushless motor; and a button disposed on a front side ofthe second switch in a front-rear direction, the button being movable inthe rearward direction to depress the second switch.
 22. The power toolaccording to claim 21, wherein a bumper is fixed to a front part of thehammer case.
 23. The power tool according to claim 22, whereinforward-most screw boss parts in the motor housing are disposed rearwardof the second switch in the front-rear direction.
 24. The power toolaccording to claim 22, wherein the second switch is disposed below andrearward of the bumper.
 25. The power tool according to claim 21,wherein: the trigger is exposed at a front surface of the upper-endportion of the handle part, and the button is exposed at a front surfaceof the lower-end portion of the motor housing.